74AHC_AHCT257_2 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 02 — 9 May 2008 5 of 16
NXP Semiconductors
74AHC257; 74AHCT257
Quad 2-input multiplexer; 3-state
6. Functional description
[1] H = HIGH voltage level;
L = LOW voltage level;
X = don’t care;
Z = high-impedance OFF-state.
7. Limiting values
[1] The input and output voltage ratings may be exceeded if the input and output current ratings are observed.
[2] For SO16 packages: above 70 °C the value of P
tot
derates linearly at 8 mW/K.
For TSSOP16 packages: above 60 °C the value of P
tot
derates linearly at 5.5 mW/K.
Table 3. Function table
[1]
Control Input Output
OE S nI0 nI1 nY
HX XX Z
LH XL L
XH H
LLXL
HX H
Table 4. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134). Voltages are referenced to GND (ground = 0 V).
Symbol Parameter Conditions Min Max Unit
V
CC
supply voltage −0.5 +7.0 V
V
I
input voltage −0.5 +7.0 V
I
IK
input clamping current V
I
< −0.5 V
[1]
−20 - mA
I
OK
output clamping current V
O
< −0.5 V or V
O
>V
CC
+ 0.5 V
[1]
−20 +20 mA
I
O
output current V
O
= −0.5 V to (V
CC
+ 0.5 V) −25 +25 mA
I
CC
supply current - +75 mA
I
GND
ground current −75 - mA
T
stg
storage temperature −65 +150 °C
P
tot
total power dissipation T
amb
= −40 °C to +125 °C
[2]
- 500 mW
